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The Copernicus Marine Service reports, October 2018: The Copernicus Marine Service has published the 2nd Ocean State Report (OSR), an extensive analysis on the state of the ocean over the last quarter of a century. An accompanying summary has also been published that highlights some specific key findings of the report along with scientific content designed to boost ocean literacy among the general public and to deliver information for decision makers.
The Ocean State Report is a thorough and periodically released report that covers the state of the European seas and the global ocean and serves as a reference for marine data and value-added marine information for the European Union, the general public, citizens and the international community. it provides a 4-D view (ocean reanalyses over time) from above (satellite data) and directly from the interior (in-situ measurements) of the blue (e.g. physical), white (e.g. polar), and green (e.g. biogeochemical) ocean.

A relatively new publication, the first Ocean State Report was published last year. The first edition was honoured with the Institute of Marine Engineering, Science and Technology (IMarEST) Denny Medal, an annual award for the most worthy paper published with the Journal of Operational Oceanography (JOO).

OSR 2 Highlights:

Warming of the Ocean and Sea Level increase.

Over the past quarter of a century, the global ocean and the European seas are warming and the sea level is rising, and a number of record-breaking extreme events occurred in Europe.

Global sea level is rising at a rate of 3 millimetres per year.

About 30-40% of this sea level rise is due to the thermosteric (warming) effect (water expands when heated).

Sea level rise in European seas increased at a rate of 2.5 to 4 millimetres per year.

Global ocean heat content (heat absorbed by the ocean) increased at a rate of 8 watts (heat) per metres squared. About 93% of the excess heat created by human activities on Earth is absorbed by the ocean.

Changes in Polar Sea ice.

Over the past quarter of a century, global sea ice melted at a pace far faster than ever observed since our earliest records dating back to the 1980s and there was a record sea ice extent low at both poles during the year 2016.

In the Arctic, sea ice extent is decreasing at a rate of 6.2% per decade, while sea ice volume has decreased at a rate of 15.4% per decade. During the 1990s there was a relatively stable carbon uptake in the global ocean and a sharp increase in the ocean’s uptake of carbon since the beginning of the 2000s.

Changes in Ocean Currents.

Driven by long-term variability rather than an ongoing trend, the Atlantic Meridional Overturning Circulation (AMOC) strength has weakened since about 2005,and the Gulf Stream has decelerated over the past 25 years.

Carbon Uptake by the Ocean

During the 1990s there was a relatively stable carbon uptake in the global ocean and a sharp increase in the ocean’s uptake of carbon since the beginning of the 2000s. [Marinet observes: an increase in carbon uptake leads to reduced alakalinity (acidification) of the ocean which, in turn, impacts upon marine life’s ability to access and utilise calcium carbonate for shell structure and skeletal purposes.

Changes in Chlorophyll production.

Over the past two decades, ocean chlorophyll has increased in high latitudes and in the European Seas (except for the Black Sea), and decreased in the tropical ocean.

Deoxygenation of the Ocean.

Ocean deoxygenation in the European seas is reported and detailed for the Black Sea, where there has been a deoxygenation trend reported over the past 60 years.

Essential Ocean Variables (EOV) are a group of variables widely understood to be essential for understanding the state/health of the ocean and changes in the marine environment in line with climate change. Examples: sea level, sea ice extent, etc.

In addition, eleven different Essential Ocean Variables (EOV) are analysed in the report. In this OSR 2, four new variables have been added (sea surface salinity, nutrients, sea-to-air CO2 flux and surface wind).

Introduced by the Global Ocean Observing System (GOOS), monitoring essential climate and ocean variables is required to support the work of the United Nations Framework Convention on Climate Change, the Intergovernmental Panel on Climate Change (IPCC) and many marine industries and services. In the coming years, new variables will be added as understanding, needs, and technology evolve.

Marinet observes: There is an apparent discrepancy in the News Release as to the heat content absorbed by the ocean in the Copernicus report. One statement in the News Release says it is 8 watts and the other statement says it is 0.8 watts. Please be advised and consult the full text in order to resolve this matter of accuracy and correctness.